fix(webhooks): cast json provider_config for atomic jsonb merge (#5249)

updateWebhookProviderConfig built a DB-side merge with jsonb operators
(COALESCE(provider_config, '{}'::jsonb) || $1::jsonb), but the
provider_config column is json, not jsonb. Postgres cannot apply jsonb
merge operators to a json column, so every polling state write failed
with "could not convert type jsonb to json" — silently breaking
historyId/lastCheckedTimestamp/pageToken/lastSeenGuids persistence for
all polling webhooks (Gmail, RSS, Google Sheets/Drive, Outlook, IMAP)
since the atomic-merge change landed.

Cast the column to jsonb for the || / - merge and cast the result back
to json for storage, matching the existing pattern in subscription.ts.

apps/sim/lib/webhooks/polling/utils.test.ts

@@ -7,7 +7,7 @@ const { mockUpdate, mockSet, mockWhere, sqlCalls } = vi.hoisted(() => ({
   mockUpdate: vi.fn(),
   mockSet: vi.fn(),
   mockWhere: vi.fn(),
-  sqlCalls: [] as Array<{ values: unknown[] }>,
+  sqlCalls: [] as Array<{ strings: readonly string[]; values: unknown[] }>,
 }))
 
 vi.mock('@sim/db', () => ({ db: { update: mockUpdate } }))
@@ -23,8 +23,8 @@ vi.mock('@sim/db/schema', () => ({
   workflowDeploymentVersion: {},
 }))
 vi.mock('drizzle-orm', () => ({
-  sql: (_strings: readonly string[], ...values: unknown[]) => {
-    const node = { values }
+  sql: (strings: readonly string[], ...values: unknown[]) => {
+    const node = { strings, values }
     sqlCalls.push(node)
     return node
   },
@@ -50,6 +50,10 @@ function allInterpolatedValues(): unknown[] {
   return sqlCalls.flatMap((c) => c.values)
 }
 
+function allSqlText(): string {
+  return sqlCalls.map((c) => c.strings.join('')).join(' ')
+}
+
 describe('updateWebhookProviderConfig (atomic jsonb merge)', () => {
   beforeEach(() => {
     vi.clearAllMocks()
@@ -77,4 +81,14 @@ describe('updateWebhookProviderConfig (atomic jsonb merge)', () => {
     expect(allInterpolatedValues()).toContain(JSON.stringify({ historyId: 'h1' }))
     expect(allInterpolatedValues().some((v) => Array.isArray(v))).toBe(false)
   })
+
+  it('casts the json column to jsonb for the merge and back to json for storage', async () => {
+    await updateWebhookProviderConfig('wh-1', { historyId: 'h1', cleared: undefined }, logger)
+
+    const sqlText = allSqlText()
+    // Column (interpolated as a value) is cast to jsonb: `COALESCE(<col>::jsonb, ...)`
+    expect(sqlText).toContain('COALESCE(::jsonb')
+    // Merge runs in jsonb space, result cast back to the json column: `(<expr>)::json`
+    expect(sqlText).toContain(')::json')
+  })
 })

apps/sim/lib/webhooks/polling/utils.ts

@@ -148,8 +148,13 @@ export async function runWithConcurrency(
 }
 
 /**
- * Read-merge-write pattern for updating provider-specific config fields.
+ * Atomically merge provider-specific config fields into `webhook.provider_config`.
  * Each provider passes its specific state updates (historyId, lastSeenGuids, etc.).
+ *
+ * The column is `json` (not `jsonb`), which has no merge operators, so the existing
+ * value is cast to `jsonb` for the `||`/`-` merge and the result cast back to `json`
+ * for storage. Casting is required — a bare `jsonb` expression cannot be assigned to
+ * the `json` column.
  */
 export async function updateWebhookProviderConfig(
   webhookId: string,
@@ -164,12 +169,13 @@ export async function updateWebhookProviderConfig(
       else defined[key] = value
     }
 
-    const merged = sql`COALESCE(${webhook.providerConfig}, '{}'::jsonb) || ${JSON.stringify(defined)}::jsonb`
+    const merged = sql`COALESCE(${webhook.providerConfig}::jsonb, '{}'::jsonb) || ${JSON.stringify(defined)}::jsonb`
+    const nextConfig = removedKeys.length > 0 ? sql`(${merged}) - ${removedKeys}::text[]` : merged
 
     await db
       .update(webhook)
       .set({
-        providerConfig: removedKeys.length > 0 ? sql`(${merged}) - ${removedKeys}::text[]` : merged,
+        providerConfig: sql`(${nextConfig})::json`,
         updatedAt: new Date(),
       })
       .where(eq(webhook.id, webhookId))